Timer



July 31, 1951 R. c. DARNELL TIMER 2 Sheets-Sheet Filed May 1'7, 1946 INVENTOR.

July 31, 1951, R. c. DARNELL 2,562,378

TIMER Filed May 17, 1946 2 Sheets-Sheet 2 IN VEN TOR; E- (Luz/ em Patented July 31, 1951 UNITED. stun PATENT OFFICE IIIMER RexDIDarnelLDexter, Mich., assignor to King- Seley Corporation, .Ann Arbor, Mich.,..a.cr-

poration of Michigan The present invention relates to timers of the. type-which are used. to time the cycleof operation ofany'apparatus-suchasa stove, washing. machineor the like; andwhichare operative. either to initiate or terminates.- an operating. 5 cycle after a: predetermined-time interval orto, actuate a signal device .-for.the-guidance of .theoperator.

One of the objects-of the present invention .is toprovide in=a timer of the -type-mentioned an. in improved signal actuator.- cocking and. tripping. mechanism.

Another objection-is to provide acockingand. trippingmechanism for the signal actuator. which will:relieve the main.-arborvot-thetimer of, the frictional load. incident to, holding. the actuator. incocked position.

Another object of the invention is to provide in a mechanism. of? the typezmention'edw means ior: adjustingthetripping point of .the mechanism 20. with reference to. the-rotational position of the: main arbor.

Another object of theinvention is to provide: an. improved mechanical: limit: stop. mechanism1 for limiting rotation of the arborrimbothzdirec tions;

A further object is to PIQVidETIIlGitDS for re-;- cooking.- the actuator in the event that:it is. accidentally tripped while? the:- timing arbor. is v out of tripping position.-

A further object is to provide-improved means for' rendering. the timing. mechanism inoperative in one position of the arbor.

Other objects. and advantages of" theinvention wi-llbecome apparent from'the following specification, the accompanyingadrawings and 'the ap pendedclaims- In the drawings? Figure 1 isan elevation view of the timing mechanism with the outer casing and one of the 40.-

movement plates removed to show the interior construction;

Figure 2 is-a view similar to Figured with only thecasing removed, showing: the mechanism mountedon the exterior. of one of the movement: 45.-

plates;

Figure 3 is a viewsimilar to Figure. =1; showingthe parts in a different-positiom-and Figures iaand 5 are fragmentary views showing.

a portionzofzthe.mechanismonan enlarged scale. 7

Inasmuchas' the type: ofzitimer to which thepresent inventior'rrelates: may to. a Jargfi extent be conventional .in construction; only-"sozmuchnf thedetailsof. constructiorrare :shownzas-are nee:-

essary 'to; fully? understandfi'tim features- I of the;

present invention... For further details. ofone suitable. type. oftimer to which the present. in?

ventionrelates, referencemay be hadto. ap.-.

Serial No.. It is suflicientto;

plicants copending. application, 659,764, .filed April 5.; 1946. note here that the mechanismordinarily com.-

prisesa casing containing. anysuitable form of. clock mechanism mounted between a pair. of.

movement plates in the. usual manner and a spring operated-signal actuating device which is.

cocked when thetimer issetto thedesired tim"v ing cycle and which, When tripped, .either rings a bell 0r operates an electrical switch.

ofreturn ofthearbor tostarting position is com trolled bythe clock mechanism, andthe actuator. is tripped upon-return of the arborto starting; position, thus operating... aa signal, an electrical switch orother suitable'device.

Referring to Figures. 1 and'2, the mechanism of thepresent. invention is shown incorporated. in .a timer having atclockmechanism-carried by; andbetween ,a' pair of movement plates I and}. The clock mechanism includes a main arbor 3'- suitably, iournaled for rotation. with. respect to themovementplatesand connected in the usual. manner through a, train of gearsto a. verge-typeescapement comprising an escape wheel 4, a verge. arm Band a balance wheel 6 carried by a balance. stafi I. A mainspring, not'shown, associated with. the. arborv 3, normally. tends to:rotate.the arbor.- in a clockwise direction,pascviewed.in'Figures"1. and .2, under" control of:theescapement'mechaa nism. and. associated; gear. train; in: the. usual;

manner.

As best shown in-:Figure .l, the-movement-plate I carries a pivot pin 8 upon which is pivoted a.

signal actuator-- which, in'itheillustrated form of the. invention, comprisesra bell hammer-9.. The actuator!) is:normally urged lHTBfiClOCkWiSB direc-.- tion about the pin B-bymeans ofza relatively stiff spring. ID, one end.of.which-isihookedat H over a notch .inthe.movementcplateel and theotherr overa projection] 2 on:the; actuator lever 9.-

one; end crab-shaped. lever. l1.

pin l3 carried by the movement plate I, and the opposite end of the lever is provided with a roller l9, which. projects through an arcuate slot 29 in the plate I, as best shown in Figure 2.

The actuating lever 9 and the connected link age are illustrated in Figure l in the tripped po-- sition which they assume after the arbor 3 is returned to its starting or zero position and the mechanism has been tripped. It will be observed that the spring I!) urges the mechanism into the position illustrated in Figure 1, in which position the parts are held against further movement by engagement of roller l9 at the end of the slot 20.

In order to prevent tilting of the U-shaped lever I! with respect to a plane parallel to the movement plates, the lever is provided with a projecting arm 21, the outer end of which is bent toward and engages the inner surface of the movement plate 1 adjacent its periphery. This is necessary inasmuch as the end of the U-shaped lever which is connected to link I is offset with respect to the main body of the lever l1 and lies in a plane spaced at a greater distance from plate I than does the main body of the lever.

As best shown in Figure 2, the mechanism for cocking the actuating lever 9 comprises a spiral cam disk 22 having a more or less radial flange 23 which is bent toward the movement plate I into the plane of the roller [9 on lever ll. As a result of this arrangement, counterclockwise rotation of the arbor 3 will cause the flange 23 to engage the roller l9 and force the latter downwardly in the slot 29, as viewed in Figure 2. This swings the lever 11, link l5 and the actuating lever 9 into the cooked position illustrated in Figure 3.

It will be observed that in the cocked position, the toggle linkage has been swung slightly past dead center inasmuch as pin [6 is located slightly to the left of a line connecting the axes of pins l4 and I8. It will be apparent, therefore, that when the flange23 of the cooking cam 22 forces the roller l9 downwardly in slot sufiiciently to swing the toggle linkage to a slight extent past dead center, the spring ID will then act to carry the toggle linkage to a further extent past dead center, thereby shifting the roller l9 entirely out of engagement with the cocking cam 22.

This cocking movement is finally limited by engagement of the roller [9 with the lower end of the slot 20, as viewed in Figure 2, at which time the parts assume the position shown in Figure 3. Under these conditions the spring it, instead of tending to effect a tripping operation, actually serves to hold the actuating lever 9 in cocked position. However, in order to trip the mechanism, it is only necessary to shift the pivot pin I6 slightly past its dead center position in the opposite direction, whereupon the spring Iii will actuate the lever 9 to operate a signal or switch.

Means are provided for shifting the pivot pin Hi from its over-center position of Figure 3 in order to trip the actuating lever upon return of the arbor to starting position by the clock mechanism; and this means is combined, in accordance with the present invention, with mechanism operative to positively limit rotation of the arbor in both directions. This mechanism, as best shown in Figure 2, comprises a lever 24 pivoted by means of a pin 25 on the movement plate l and a second lever 26, which is connected to the lever 24 by means of a frictional rivet 21. The rivet 21 is so constructed that it pivotally con- 4 nects the levers 24 and 26 but holds them in tight frictional engagement with each other, with the result that they cannot be angularly displaced with respect to each other except by exertion of a substantial force.

In the region in which the levers 24 and 26 overlap, lever 24 is provided with a small circular opening 28, which is aligned with the center of a slot 29 in the lever 26. When it is desired to adjust the angular position between the levers 24 and 26, such adjustment is effected by inserting into the slot 29 the end of a circular rod-like tool having a diameter equal to the width of the slot 29 and having a projecting eccentrically located pin, the axis of which extends parallel to the rod and which is adapted to fit the opening 28. After the pin on the end of the rod-like tool is fitted in the opening 28, the tool is rotated and, by reason of the eccentric location of the pin, the tool will shift the angular position of lever 26 relative to that of lever 24, as desired.

Lever 24 is provided with a projection 30, which extend through a suitable opening formed in the plate I and into the path of the toggle link I5. Lever 26 is provided with a flange 3|, which projects in the opposite direction into the path of movement of the flange 23 on cam 22. Lever 26 also is provided with a projecting right-angled arm 32 adapted to engage a stationary pin 33 carried by the movement plate I. The arm 32 is normally held in engagement with the pin 33 by means of a spring 34, which is wrapped around the pins 25 and 21 and has its free end engaging the pin 33 in such a manner as to tend to cause a rotation of the levers 24 and 26 in a counterclockwise direction about the pin 25, as viewed in Figure 2. As a result of this construction, counterclockwise rotation of the levers 24 and 26 about the pin 25 is limited to the position shown in Figure 2 and, consequently, when the arbor returns to its starting position, as indicated in Figure 2, the flange 23 on the cam 22 will engage flange 3| on the lever 26. This will positively limit further clockwise rotation of the arbor and thus bring the timer to a stop in its zero position. It will be observed that the positive stop thus provided does not involve the exertion of any force on the levers 24 and 2B tending to cause a relative rotation of one of the levers with respect to the other about the friction rivet 21.

During the return movement of the arbor to zero position under the influence of the clock mechanism, the toggle lever l 5 will be in engagement with the projection 30 of lever 24, as illustrated in solid lines in Figure 3, thus holding the arm 32 of lever 26 out of contact with the stop pin 33. As the arbor approaches its zero or stop position, flange 23 of cam 22 engages flange 3| on lever 26 and thus swings levers 24 and 26 about the pin 25 in a counterclockwise direction. This swings the projection 39 on lever 24 from the solid line position shown in Figure 3 to the dotted line position shown in the same figure, thus shiftin toggle link pin l6 over the dead center position and thereby tripping the actuating lever 9. By this time the cam 22 will be in approximately the position shown in Figure 2, thus permitting return of roller l9 to the upper end of slot 2!). Immediately after the tripping operation occurs, arm 32 on lever 26 engages the stop pin 33 and thereby stops further clockwise rotation of the arbor. The angular adjustment provided between the levers 24 and 26, as previously described, thus permits an adjustment of the distance between the projection 30 and the aueaare; s

point resultin from:the unavoidable. tolerances.

inzmanufacture;

The; period :1 of time.v through :which the'timer;

operates depends: upon. the. degree.v of. angular:

counterclockwise; rotation. .of: the. arborz 3 during;-

setting; the. maximum .period; corresponding; to La." rotatiomotthe arbor throughanangle, of 1 approxe 1 imately 360?; The :previously; described: mechanism, operates 1 tozpositively; limit ;.settingmovement .toza maximum angle:o;360.. Thisaresults:

from the: factxthat .upona. counterclockwisesroe 5-- tation of; arbor? 3. from::tl1'e:.-positio1r: shown; im Figure; -2,..th.e;flange 23-3onrthe;.cam:22;will .evenr tually engage the rear side of the flange 3| on lever926 Suchengagement swings the lever 26 and its associated lever 24 in a clockwise direction about the pin1'253until thetfl'ange: 3| engages the stop pin 33-.- This .efiects aspositive. abutment which will prevent further counterclockwise: rotation of the .arbor. Again. it will be noted that this limited a'butmen't isso*constructed'that the 25 forces imposed upon it do not'stend to causes-any-v relative; rotationbetween the lovers 24 and 26. Moreover; it; will .be. .noted. .thatisince lever 25 has a lost motionurelationship. with; respect to the stopvpin 33, a'full..36.0 rotationiofthe arbor be.

tween its two limitingrstops-iis. provided.

For some purposes it is desirable to provide means ier preventing unwinding rotation ot th'e' arbor-afterit has been rotated -in' a setting "direction to the maximum-extent. Such an arrangement is advantageous, for example, when the timer is utilized to operate a switch which terminates the cycle of operation of a machine. In that case, when it is desired to operate the machine continuously or for a period in excess of that provided by the timing mechanism, the arbor may be rotated through its maximum setting movement, whereupon the timing mechanism will be locked, with the result that no unwinding rotation occurs until after the arbor is manually displaced from its maximum position. As best shown in Figure 2, means for this purpose are provided comprising an arm 35 pivoted on plate I by a pin 36. The terminal portion 31 of the arm 35 is normally held in a position bearing against the arbor 3, in the manner best shown in Figure 4, by means of one end 38 of a wire spring which i clamped to the arm by means of a bent-over tab 39 and which bears against a bent-up lug 40 on the movement plate. The

opposite end 4! of the spring projects in a direction generally parallel to the arm 35 and is bent at right angles in such a manner as to enter a slot 42 formed in the movement plate I, the inwardly bent end being normally located in the position indicated in Figures 1 and 3 at a point spaced to a slight extent from the periphery of the balance wheel 6 of the escapement mechanism.

The arbor 3 is provided with a notch 44 which assumes the position relative to the terminal portion 31 of the arm 35 which is illustrated in Figure 4 when the arbor is in its zero or stop position. In order to set the timer, the arbor 3 is rotated in a counterclockwise direction, as

viewed in all figures of the drawings, and it will be apparent from Figures 4 and 5 that upon competion of a counterclockwise rotation through an angle of 360, the notch 44 will carry the terminal portion 31 of the arm 35 into the position 6 shown; in: Figure: 5. Thistspermits the: BIIIIJIF; to swing? in; as counterclockwise? directior1;.. as: viewed in Figure 2, understhe infiuencaofispringg 38;? thereby? pressing? the: end; 41- ofitheav wire against." the periphery of thezbalance: wheel; A; very 'li'ght'zpressuresbetween:theewire and thebaleance wheellisrsuflicientito'zprevent operation of-:the;.-

clock mechanismand; consequently;returnioftthe arbor to its zero position. The timeriwill; there fore, remain in its maxiumu;setting:positionxirrdefinitely;

When; it isr-desired; to return": the arborto zero :position; either :manually =or:under: thez control vottheclock mechanism, the:- arbor is: simplyrotated in a; clockwise: directiomthrough: a very small angleLSufiicient torswing the arm: 35:inza1 clockwise: directionea's .viewed iniEigure -2'. This:- disengagesi; the: wire 4| fromtthe: balancezw'heeli and permits goperation of thezclockimechanismz.

An -.importantffeatureaof .thefull windiholdingr. mechanism above; described: resides in: the: factthat it permits a full36.0- rotation: of. thezzarbor; from. the zeroposition: to'the full: wind position:

and yet causes operationof: the-holdingmech--. I .anism' only Whenrthe; arbor; is-iin' its;full wind? I position. This: results frompthe'fact that-theterminal portion. 31 of. the arm 3.5 can only; ene ter: the notch. 44 and "be swung to thea holding: positionillustrated in Figureb "upona' counter.- clockwise I rotation of the arbor}. as. viewed? in;

Figure 5, to. the;position:shown;inrFigure 5:. Roe

tation' of thearbor in *the.oppositeadirectiorrinto? the same a position does; not-t permit: entry. of the s terminal portion: 31- into the notch.- COIISB'r- :"quently, the holding means does-not; stop the? clock mechanism at or near the end of the unwinding movement. This is desirable since otherwise it wouldv be necessary to accurately correlate the operation of the holding mechanism with the zero point on the timer dial and the point of actuation of the signal actuator.

It should be noted that the cocking cam 22 has a peripheral surface lying in a generally spiral path beginning and ending at the cooking flange 23. As a result of this form, the actuating mechanism or hammer 9 may be recocked by a reverse or clockwise rotation of the arbor 3, as viewed in Figure 2, in the event that the hammer mechanism is accidentally tripped before the cooking cam returns to its tripping or zero position. In that case, it should be noted that if the timer is dropped or subject to a severe jar when the hammer mechanism is cooked, the toggle linkage may be jarred over the dead center position and thereby tripped while the arbor was in its full wind or a partially wound position. In that case, in the absence of the spiral peripheral cam surface on the cocking cam, it will be impossible to return the arbor to its zero position and, therefore, impossible to restore the timer to an operative condition. It will be appreciated that in the construction illustrated, after such an accidental tripping of the actuator 9, the roller I9 will move upwardly in the slot 2|], until it moves into contact with the spiralshaped peripheral surface of the cam disk 22 which it will be appreciated will be turned in a counterclockwise direction, as viewed in Figure 2, during the cooking and setting of the timer. The actuator 9 may be recocked by rotating the disk 22 in a clockwise direction, as viewed in Figure 2, during which movement the roller [9 is positioned downwardly in the slot 20 to its cocked position by the spiral-shaped peripheral surface of the cam disk 22. If this feature of 7 the invention is not desired in any case, the cocking cam need only constitute a radially projecting arm carrying the flange 23.

While only one form of the invention is shown and described herein, it will be apparent that variations in the design and details of construction may be indulged in without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. In a timer having a frame, a spring operated signal actuator, means for holding said actuator in acocked position, a rotatable arbor adapted to cock the actuator and render said means operative to hold said actuator in said cocked position on rotation in one direction from a starting position, a member pivoted on the timer frame in dependently of the arbor and adapted to render said means inoperative to hold the actuator in said cocked position, a second member, means adjustably mounting said second member on the first member, abutment means on the timer frame adapted to engage said second member and. thereby limit pivotal action of said members in both directions, and means on the arbor adapted to engage said second member at the end of a predetermined degree of rotation of the arbor in said one direction and at the end of a return rotation to starting position whereby said second member provides a positive stop in both directions of rotation, said second member being adapted to engage said first na'med means to cause a tripping movement of the first member as it is moved against said abutment means on return of the arbor to starting position.

2. In a timer having a frame, an arbor rotatably mounted on said frame, a spring operated signal actuator mounted on said frame, means on the arbor for engaging and cocking said actuator when said arbor is rotated away from starting position, means mounted on said frame adapted to engage said last named means for limiting the rotation of the arbor, means mounted on said arbor for tripping the actuator on return of the arbor to starting position, and means mounted on said arbor and operable in the event that the actuator is accidentally tripped while the arbor is displaced from the starting position, in response to movement of the arbor toward starting position, to engage and recock said actuator whereby the actuator is placed in proper position to cooperate with the tripping means.

REX C. DARNELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 127,641 Pieper June 4, 1872 2,103,257 Hastings Dec. 28, 1937 2,253,929 Campbell Aug. 26, 1941 2,349,631 Lindstrom et a1. May 23, 1944 FOREIGN PATENTS Number Country Date 772,612 France Aug. 18, 1934 797,841 France Feb. 24, 1936 

